Astrophotography with ImageMagick

I am not a very dedicated (or experienced) astrophotographer, but every now and then I feel like taking a photo of the sky. On high ISO and long exposures, you’ll find plenty of noise. Also, if you live as close to a city as I do, you’ll want to subtract background and correct for field distortions, to improve the (contrast-enhanced) images. Here is how to do that from the command line, using ImageMagick.